1. Field of the Disclosure
The present disclosure is related to chemical mechanical planarization pad conditioners, and more particularly CMP pad conditioners incorporating particularly hard, carbon-containing materials.
2. Description of the Related Art
In the fabrication of integrated circuits and other electronic devices, multiple layers of conducting, semiconducting, and dielectric materials are deposited onto and removed from a surface of a semiconductor wafer. As layers of materials are sequentially deposited and removed, the uppermost surface of the wafer becomes non-planar. Because subsequent semiconductor processing requires the wafer to have a flat surface, the wafer needs to be planarized. A wafer surface that is not sufficiently planar will result in structures that are poorly defined, with the circuits being nonfunctional or exhibiting less than optimum performance. Chemical mechanical planarization (CMP) is a common technique used to planarize or polish workpieces such as semiconductor wafers.
During a typical CMP process a workpiece is placed in contact with a polishing pad and a polishing slurry is provided on the pad to aid in the planarization process. The polishing slurry can include abrasive particles which may interact with the workpiece in an abrasive manner to remove materials, and may also act in a chemical manner to improve the removal of certain portions of the workpiece. The polishing pad is typically much larger than the workpiece. The polishing surface of the pad is generally a polymer material that can include certain features, such as micro-texture suitable for holding the slurry on the surface of the pad. Moreover, during a polishing operation, a pad conditioner is typically employed to move over the surface of the polishing pad to clean the polishing pad and properly condition the surface to hold slurry.
Polishing pad conditioning is important to maintaining a desirable polishing surface for consistent polishing performance, because over time the polishing surface of the polishing pad wears down, smoothing over the micro-texture of the polishing surface. Additionally, debris from the CMP process can clog the micro-channels through which slurry flows across the polishing surface. Conventional polishing pad conditioning is achieved by abrading the polishing surface mechanically with a pad conditioner, typically consisting of diamonds placed on the surface of a substrate. However, such conditioners typically suffer from several flaws, including among others, diamond pop-out, variable protrusion height of the diamonds above the surface of the substrate, uncontrolled diamond grain orientation, and variable diamond grit positioning.
Accordingly, the industry continues to demand improved CMP pad conditioners and methods of forming thereof.